DESCRIPTION: The proposed effort is expected to result in preliminary evaluation of the potential for weighted and dynamically updated associations to provide improved access and ranking of medical information in CANCERLIT (NLM) database in support of a Phase II effort to develop a "web" based interactive information retrieval system (MEDQ) that uses the technology. The information retrieval technology that provides this capability uses an innovative context-sensitive spreading-activation measure to compute relevance measures to rank information objects. Term-relative normalization is used to favor query terms with higher discrimination value and provides a balance between within-query considerations of term importance and between-object (or within-term) considerations of object relevance. Fuzzy searches are inherently supported by this approach. This technology is being used to enhance Mosaic, WAIS, and WWW servers under NASA Contract NAS 9-19046. The evaluation design is based on the design used in a recent study of SAPHIRE, an experimental system for automated indexing and retrieval. The SAPHIRE study provides a baseline for this evaluation.